Peptide library / Skin & aging / Melanotan II
Melanotan II
An injectable alpha-MSH analog used for tanning and libido, with known safety warnings.
Full analysis available. Melanotan II is under FDA compounding review, and we cover it in depth with the committee vote and our Peptide Evidence Index. Read the full Melanotan II analysis →
Effects studied or claimed
What it is used or promoted for, and where each effect has actually been seen
- TanningSmall human studies
- Erectile function and libidoSmall human studies
How it is thought to work
Melanotan II activates several melanocortin receptors, causing skin darkening and effects on sexual arousal and appetite.
What the evidence shows
Small studies from the 1990s showed tanning and erections in men. Regulators in several countries warn against unregulated products.
Safety and unknowns
Nausea, flushing and changes to moles have been reported, and cases of melanoma have been discussed in case reports.
Regulatory status
Not FDA-approved, and the FDA has warned consumers. See our full Melanotan II profile.
Regulatory status changes quickly. This entry was last reviewed on 27 October 2026. Confirm current status with the FDA before relying on it.
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General information, not medical advice. Do not buy or inject unregulated peptides.